On Mon, Apr 10, 2023 at 08:59:33PM +0100, Konstantin Ananyev wrote:
> 06/04/2023 01:45, Tyler Retzlaff пишет:
> >Forward declaration of a typedef is a non-standard extension and is not
> >supported by msvc. Use an int instead.
> >
> >Abstract the use of the int/enum rte_cpu_flag_t in function parameter
> >lists by re-typdefing the enum rte_cpu_flag_t to the rte_cpu_flag_t
> >identifier.
> >
> >Remove the use of __extension__ on function prototypes where
> >rte_cpu_flag_t appeared in parameter lists, it is sufficient to have the
> >conditionally compiled __extension__ at the non-standard forward
> >declaration site.
> >
> >Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
> >---
> > lib/eal/include/generic/rte_cpuflags.h | 12 +++++++-----
> > 1 file changed, 7 insertions(+), 5 deletions(-)
> >
> >diff --git a/lib/eal/include/generic/rte_cpuflags.h
> >b/lib/eal/include/generic/rte_cpuflags.h
> >index d35551e..87ab03c 100644
> >--- a/lib/eal/include/generic/rte_cpuflags.h
> >+++ b/lib/eal/include/generic/rte_cpuflags.h
> >@@ -44,8 +44,12 @@ struct rte_cpu_intrinsics {
> > /**
> > * Enumeration of all CPU features supported
> > */
> >+#ifndef RTE_TOOLCHAIN_MSVC
> > __extension__
> >-enum rte_cpu_flag_t;
> >+typedef enum rte_cpu_flag_t rte_cpu_flag_t;
> >+#else
> >+typedef int rte_cpu_flag_t;
> >+#endif
>
>
> Just curious what exactly MSVC doesn't support here?
> Is that construction like:
> enum rte_cpu_flag_t {....};
> enum rte_cpu_flag_t;
> ...
> Or something else?
Forward declaration of an enum is non standard. It's probably only
allowed by gcc as an extension because gcc will make some kind of
implementation specific promise for it always to be `int` size by
default (assuming no other -foptions).
If the enum was defined before reference it would probably be accepted
by msvc since it could 'see' the definition and know the integer width
in use.
>
>
> > /**
> > * Get name of CPU flag
> >@@ -56,9 +60,8 @@ struct rte_cpu_intrinsics {
> > * flag name
> > * NULL if flag ID is invalid
> > */
> >-__extension__
> > const char *
> >-rte_cpu_get_flag_name(enum rte_cpu_flag_t feature);
> >+rte_cpu_get_flag_name(rte_cpu_flag_t feature);
> > /**
> > * Function for checking a CPU flag availability
> >@@ -70,9 +73,8 @@ struct rte_cpu_intrinsics {
> > * 0 if flag is not available
> > * -ENOENT if flag is invalid
> > */
> >-__extension__
> > int
> >-rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature);
> >+rte_cpu_get_flag_enabled(rte_cpu_flag_t feature);
> > /**
> > * This function checks that the currently used CPU supports the CPU
> > features
